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Leveraging electrochemistry, a new synthesis of non‐natural derivatives of itaconic acid is proposed by utilizing carbon dioxide (CO2) as a valuable C1 synthon. An electrochemical cross‐electrophile coupling between allenoates and CO2 was targeted, allowing for the synthesis of both mono‐ and di‐carboxylation products in a catalyst‐ and additive‐free environment (yields up to 87 %, 30 examples). Elaboration of the model mono‐carboxylation product, and detailed cyclovoltammetric, as well as mechanistic analyses complete the present investigation. [ABSTRACT FROM AUTHOR]

A new nickel catalyzed cross‐electrophile coupling for accessing γ‐lactams (isoindolinones) as well as γ‐lactones (isobenzofuranones) via carbonylation with CO2 is documented. The protocol exploits the synergistic role of redox‐active Ni(II) complexes and AlCl3 as a CO2 activator/oxygen scavenger, leading to the formation of a wide range of cyclic amides and esters (28 examples) in good to high yields (up to 87 %). A dedicated computational investigation revealed the multiple roles played by AlCl3. In particular, the simultaneous transient protection of the pendant amino group of the starting reagents and the formation of the electrophilically activated CO2‐AlCl3 adduct are shown to concur in paving the way for an energetically favorable mechanistic pathway. [ABSTRACT FROM AUTHOR]

The first site‐selective electrochemical alkylation of tropones is realized by reacting 2‐acetoxytropones and redox‐active‐esters (RAEs). The electroreductive protocol enables the preparation of mono‐ and disubstituted tropones in high yields (up to 71%) under very mild conditions. Dedicated voltammetric measurements served for the identification of 2‐acetoxytropones as a class of valuable trapping agents of nucleophilic radical species and shed light on the whole mechanistic profile. Wide tolerance towards functional groups (27 examples) and application to late‐stage functionalization of a bioactive compound (i. e. Colchicine analogue), emphasize the synthetic impact of the present methodology. [ABSTRACT FROM AUTHOR]

The "on‐demand" capture and utilization of CO2 is effectively realized with a readily accessible dual function organic composite. The covalent and controlled derivatization of graphene oxide (GO) surface with naturally occurring arginine led to a "smart" material capable of capturing (chemisorption) CO2 from high‐purity flue‐gas as well as low‐concentration streams (i. e. direct air capture) and concomitant chemical activation toward the incorporation into cyclic carbonates. The overall integrated CO2 capture and conversion (ICCC) strategy has been fully elucidated mechanistically via dedicated computational, spectroscopic and thermal analyses. [ABSTRACT FROM AUTHOR]

The "self-adaptability" of galvanostatic electrolysis was shown to assist a multistage unprecedented chemo- and diastereoselective electrochemically promoted cyclodimerization of chalcones. The process, all involving the reductive events, delivered densely functionalized cyclopentanes featuring five contiguous stereocenters (25 examples, yields of up to 95%, dr values up to >20 : 1). Dedicated and combined experimental as well as electrochemical investigation revealed the key role of a dynamic kinetic resolution of the aldol intermediate for the reaction mechanism. [ABSTRACT FROM AUTHOR]

The development of higher‐order cycloadditions has mainly been restricted by the requisite usage of highly conjugated and reactive π‐systems. Recent years have witnessed organocatalysis as a potent mediator for several of the challenges associated herein, rendering higher‐order cycloadditions a legitimate option for achieving the selective construction of specific molecular scaffolds. These developments reinvigorate the efforts to try to understand the underlying principles for cycloadditions involving a higher number of π‐electrons than the "classical" cycloadditions; how do we properly address the impact which the addition of further π‐electrons have on the reactivity of a system? Herein, computational investigations of two model higher‐order cycloaddition systems have been performed to try to provide insights on changes in energetic barriers induced by the presence of benzofusions in a position which is unobstructive to the reactivity. With experimental substantiation as support, these studies might open up for a discussion on whether the π‐electrons of benzofused systems simply act as spectator electrons, or play a tangible role on the observed reactivity to an extent where a distinct nomenclature is meritable. [ABSTRACT FROM AUTHOR]

The utilization of CO2 as an efficient and environmentally friendly chemical analogue of CO is becoming a solid reality in the chemical scenario. CO2‐based carbonylations have started paralleling the more consolidated carboxylation procedures, opening new horizons and perspectives in the utilization of carbon dioxide as an organic C1‐containing building block. The advent of efficient and site‐selective metal‐catalyzed protocols for the fixation of CO2 into organic scaffolds, under controlled reductive conditions, contributed substantially to the development of robust, efficient, and convenient protocols. In the present Review article, a collection of the most recent examples of metal‐catalyzed CO2‐based carbonylations is documented with a particular emphasis on mechanistic aspects. [ABSTRACT FROM AUTHOR]

The chemo- and stereoselective electrochemical allylation/alkylation of ethers is presented via a C(sp3)–H activation event. The electrosynthetic protocol enables the realization of a large library of functionalized ethers (35 examples) in high yields (up to 84%) via cathodic activation of a new type of redox-active carbonate (RAC), capable of triggering HAT (Hydrogen-Atom-Transfer) events through the generation of electrophilic oxy radicals. The process displayed high functional group tolerance and mild reaction conditions. A mechanistic elucidation via voltammetric analysis completes the study. [ABSTRACT FROM AUTHOR]

New covalently modified GO‐guanidine materials have been realized in a gram‐scale synthesis and purified by an innovative microfiltration. The use of these composites in the fixation of CO2 into cyclic carbonates is demonstrated. Mild operating conditions, high yields (up to 85 %), wide scope (15 examples) and recoverability/reusability (up to 5 cycles) of the material account for the efficiency of the protocol. Dedicated control experiments shed light on the activation modes exerted by GO‐l‐arginine during the ring‐opening/closing synthetic sequence. [ABSTRACT FROM AUTHOR]

A carboxylative Ni-catalyzed tandem C–C σ-bond activation of cyclobutanones followed by CO2-electrophilic trapping is documented as a direct route to synthetically valuable 3-indanone-1-acetic acids. The protocol shows an adequate functional group tolerance and useful chemical outcomes (yield up to 76%) when AlCl3 is adopted as an additive. Manipulations of the targeted cyclic scaffolds and a mechanistic proposal based on experimental evidence complete the investigation. [ABSTRACT FROM AUTHOR]

A new type of ligand-free Ni-nanoparticles supported on rGO (size distribution average d = 9 ± 3 nm) was prepared and fully characterized via morphological (Fe-SEM), structural (P-XRD, HR-TEM), and spectroscopic (ICP-EOS, XPS) analysis tools. The metal composite was effectively employed in the unprecedented heterogeneously Ni-assisted cross-coupling reaction of aryl/vinyl iodides and thiocarboxylates. A range of sulfur-containing aryl as well as vinyl derivatives (15 examples) was achieved in high yields (up to 82%), under mild reaction conditions, and with wide functional group tolerance. [ABSTRACT FROM AUTHOR]

A dehydrogenative functionalization of styryl carbon‐carbon double bonds with triflamide is described via dual visible‐light photoredox/cobaloxime catalysis. A range of allylic triflamides (20 examples) were isolated in moderate to good yields (up to 88%) under stoichiometric acceptorless conditions. Dedicated labelling, as well as spectroscopic experiments, enabled to shed light on the concatenated photo‐ and chemo‐catalytic cycles. [ABSTRACT FROM AUTHOR]

The tandem catalytic functionalization/carboxylation of double as well as triple carbon‐carbon bonds with CO2 represent an emerging research area in synthetic organic methodology. In particular, the combination of mild reaction conditions, stoichiometric acceptor/donorless conditions (visible light photoredox catalysis) and chiral catalysts contributed to a rapid development of this intriguing research area capable of creating chemical diversity/ complexity from readily available unsaturated hydrocarbons and CO2 as a C1‐buinding block. The most recent developments in the field have been collected in the present review article and organized, based on the different sets of π‐systems/intermediates/reactive partners employed (i.e., nickelalactones, organo‐halides) as well as synthetic strategies (i.e., visible‐light photo redox catalysis). [ABSTRACT FROM AUTHOR]

The tandem catalytic functionalization/carboxylation of double as well as triple carbon‐carbon bonds with CO2 represent an emerging research area in synthetic organic methodology. In particular, the combination of mild reaction conditions, stoichiometric acceptor/donorless conditions (visible light photoredox catalysis) and chiral catalysts contributed to a rapid development of this intriguing research area capable of creating chemical diversity/ complexity from readily available unsaturated hydrocarbons and CO2 as a C1‐buinding block. The most recent developments in the field have been collected in the present review article and organized, based on the different sets of π‐systems/intermediates/reactive partners employed (i.e., nickelalactones, organo‐halides) as well as synthetic strategies (i.e., visible‐light photo redox catalysis). [ABSTRACT FROM AUTHOR]